Fifth wheel



P Jan. 30, 1940. Y H. A. rsoULlss FIFTH WHEEL Filed June 19, 1957 .s sheets-sheet 1- INVENTOR H. A. souLls VJan, '36, i940.

FIFTH WHEEL Filed June 19, 193:7v

3 'Sheets-Sheet 2 lNvENoR Jan. 30, 1940. H. A.. soULls 2,188,727

v FIFTH WHEEL v .Filemune 19, 1937 3 sheets-sheets INVENTOR Patented Jan. 30, 1940 UNITED ASTATES lrrrlaN'rv OFFICE 16 Claims.l

The purpose of this invention is to provide noleans to control the relative rotative movement oi' the tractor and the semi-trailer about the king pin of the fth wheel. In the operation of a trac- 5 tor-trailer upon the highways there is danger of the tractor-trailer jack-kniiing when the brakes are applied, especially when the vehicle is rolling over a slippery surface. The tractor skids around in-one direction and the semi-trailer at the same 10 time skids in the opposite direction, until it ends up against the cab or some other projecting part of the tractor. Jack-kniflng naturally results from instability of the tractor-trailerl train in motion. It is a general principle of stability of l5 motion that if the point of application of, the

driving force or lpropelling force is located ahead exert -a greater retarding effort than the semi.

trailer brakes and the'inertia of the semi-trailer I 30. will tend to skid the trailer wheels causing asocalled jack-knife. The skid of the semi-trailer 'wheels on a-slipping surface is apt to' happen with a sudden action, beyond the drivers control due to the fact the tires have no more re- 35 sistance to side motion than that of going ahead. However, tractor-trailer trains in which brakes are applied to the trailer wheels only, are not in practical use, because oi' the excessive tire wear and the vehicle -would be inadequate for safety at 4 higher speeds, due to lack of sufcient'retarding effort. Therefore both tractor and semi-trailer brakes must be used, as the forces which keep the tractor-trailer train in motion act at the centers ,of gravity of the tractor and of the semi-trailer respectively, and if the coupling or king pin axis moves even slightly from the line connecting the vtwo centers of gravity, a jack-kniflng eiect is produced, in that both units tend to pivot around v 50 their forward ends, in opposite directions, the turning moment on both increasing with the angle between their axis. lock the tractor and the semi-trailer against rotation with respect to each other automatically. v55 when the brakesare applied. This same resistelectrical, mechanicall or manual means.

Therefore, in my invention I l (Cl. 18S- 3) ance to pivoting may be used at any time it is deemed necessary by the drivenby the use of a manually operated hand valve. Operating conditions are at times, conductive to jack-kning of the tractor-trailer train, even when operating 5 over a dry lsurface. Loss of life and property would be eliminated by the use of my invention and would therefore make tractor-trailer train operation safe on the public highways. l

It is the object of my invention to provide a m tractor-trailer train with a lower fifth wheel that can be locked to the upper-.fifth wheel of a tractortrailer train, so as to turn together when ina coupled position. To accomplish this I mount the lower iifth wheel on a rotative base having means to apply brakes against rotation. The rotative base brake is actuated by the same-power braking system used to decelerate the vehicle. This power means can be compressed air, vacuum, hydraulic, The power means for the fifth wheel rotative base brake is applied automatically when power is applied to the tractor brakes or by operating a separate valve manually when it is desired to hold the lower fth wheel against rotation, as in coupling the tractor to the semi-trailer. The amount of braking effort that is supplied to the fth wheel rotative base brake can be varied to give greater or less resistance to the fifth wheel rotative base lbrake so that the amount of resistance can be set up to suitthe operating or vehicle requirements. The upper ilfth wheel can also be mounted on a rotating base, having means to brake against ro-v tation, if desired.

It is not necessary to have a friction brake in my device as the same results may be obtained by a lockingarrangement or by restricting the ow of a uid from a high pressure to a non-pressure side of a jack-knife resisting device, when used in resistinga turning movement about the king pin or coupling device of a tractor-trailer train and applied at a predetermined time.

It isvmy object to control the tractor-trailer trainin operating over a highway having' a surface that is slippery, or over a dry surface where the tractor-trailer train might jack-knife, so as to keep the semi-trailer from rjack-knifing the tractor, automatically when applying the vehicle brakes, because of the fact that the brake on the fth wheel is applied at the same instant that the 50 vehicle brakes are applied. Therefore, it does not allow time for the inertia oi a semi-trailer to jackknife the vehicle. The brake onthe fifth wheel can also be used in spotting the semi-trailer and in holding the iifth wheel from rotation when picking up a semi-trailer. I have elected to show the power means on my fth wheel actuated by compressed air, although vacuum, hydraulic, electric or mechanical means may be used with equal success. f

Other designs can be used to mount the brake to prevent jack-kniiing of the tractor-trailer train in which the brake or lock may be-mounted on' the tractor or semi-trailer. However, it is one of the principal objects of my invention to utilize the brake energy means to actuate the jack-knifing preventing devices simultaneously with an appliv cation of the brakes ong the tractor, or otherwise.

Other objects and advantages from the utilization of my invention will doubtless present themselves as the description proceeds, and I would have it clearly understood that I reserve unto myself all rights to the full range of equivalents', both in manner of practicing my invention and its use, to which I may be entitled under'l my invention in its broadest aspect. the purpose of the present disclosure, I have elected to describe a certain preferred design. However, as previously pointed out, this is not to be interpreted as a limitation of the scope of my invention, which may be followed with equal success in the manufacture of iifth wheels or systems for controlling tractor-trailer highway vehicles.

In the drawings: I

Fig. 1 is a conventional schematic diagram of an air braking system showing the manner of connecting and applying the compressed air used in/ the system to the fth wheel brake to control lateral motion of the tractor-trailer train about the king pin or coupling.

Fig. 2 is a plan View of the lower fifth wheel, showing the assembly mounted on the pick-up plate and the tractor frame.

Fig. 3 is a side elevation of Fig. 2, showing the lower fth wheel coupled to the upper fth wheel with the upper and lower fifth wheel lock pawl in place. This view also shows the upper fifth wheel mounted on the front end of the semitrailer.

Fig. 4 is a plan View of the upper fifth wheel andlocking pawl. The lower fth wheel is shown dotted in position.

Fig. 5 is a sectional elevation through A A of Fig. 4 showing the lock pawl, upper and lower fifth wheel and the rotary base with the brake used to control the jack-kning of the semitrailer.

In Figure l a compressor is indicated at I,.

which is driven directly from the engine crankshaft or from one of the auxiliary shafts, furnishes compressed air for brake operationY with a governor indicated at 2 serves to regulate the pressure of the air in the reservoir, indicated at 4, pressure between minimum and maximum Asettings. In operation the governor 2 functions though pipe 3, to unload the compressor dis-l charge valves when to 105 pounds of air pressure in reservoir 4 is reached. I'he compressor i is connected through pipe 5 to reservoir 4. Reservoir 4 is connected to governor 2 through pipe 6. Gauge 7 is connected into pipe 6, and indicates the air pressure in reservoir 4. Reservoir 4 safety valve 8 protects against the possibility of excessive pressure in the reservoir and complies with certain State laws The brake valve indicated at 9 controls the brake operation by directing the iiow of air from reservoir 4 to brake chambers I9 in brake application and from brake chambers I0 to atmosphere in release, has pipe For 30 connecting it to reservoir 4. Brake valve 9 has outlets connected to brake power chambers I0 which-in turn connect to leversto apply power to the tractor brakes through pipes II. The chambers, one for each wheel, convert the stored energy of the compressed air into mechanical force to apply the brakes.

Pipe I2 `connects the semi-trailer service line connection I3 while pipe I4 connects the semitrailer emergencylinel to the reservoir 4. I6

indicates cut-out cocks tothe semi-trailer connections. Pipe I1, I1 connects the brake valve 9A. to fifth wheel brake power chamber I8, while pipe 3| connects the brake valve 9A to reservoir 4. Brake valves 9'and 9A are connected to the brake pedal of the tractor so as tooperate simultaneously, as hereinafterv described. At I9 is shown a hand control valve connected to res- 9, brake valvel 9A is also opened to allow air to,

flow through pipesl 3| and I1, I'I' to iifthl wheel brake chamber l'which turns brake cam 22 by means of a partial rotation of lever 23. Cam 22 forcesflfth wheel brake shoes 24 against a drum`25, fixed vto the lower fth wheel rotary base 26. Fifth wheel brake shoes 24 are rfixed to lower fifth Wheel base 21 through plate 28 to which it is attached, by means of anchor pins 29, on which they arel fulcrumed at the opposite end to that of the cam application. Parts 25 to 28 inclusive are shown in Figure 5.. To re-l lease the brakes, brake valve 9 is allowed to close the compressed air passages to release the air vin chambers I0 through'the exhaust port in the brake valve 9.I To release the fifth wheel brake', brake valve -9A is allowedy t'o close the compressed air passages to release the air in chamber I9 through the exhaust 'port i in brake valve 9A.- Brake valves9 and 9A 'areconnected to the usual pedal Sliin the tractor cab so that they both operate together. This may be accomplished by'.

means of a yoke-like fitting 6|, embodying bifurcated portions Ii2 and 63, within which the levers of the respective valves 9 andl 9A are pinned for l relative pivotal movement, a rod 64 threaded into said fitting and having an articulated connection with said pedal arm, asat 65, interconnecting the pedal and. fitting for -conjoint movement. Should it be desired to function th'e fifth wheel brake chamber I 9 without applying the tractor brake chambers I0, hand control ,Valve I9 is operated manually, by the tractor driver and compressed air will flow through pipes 29 and '2| and I1' to fifth wheel brake chamber I8. By the application of compressed air to fth wheel brake chamber I8, without applying the tractor brake chamber, I0, hand control valve I9 is operated manually by the tractor driver and compressed air willfiow through pipes 'AIUv and 2| and I1' to fifth wheel brake chamber I8, which will apply fifth wheel brake shoes 24 against brake drum 25. To release the fth wheel brake shoes 24, the'hand control valve I9 is closed to allow the compressed air in chamber I8 and pipesA IIand 2| to flow to atmosphere. An

the pipe sections I1 and Il', to relieve the presvsure in the power diaphragms il and the pipe section I1' to permit the air to exhaust into the pipe section I1 orthe pipe 2l, as the case may be. As will be evident, when .the fifth-wheel brakes are operated, through the functioning4 of the valve 9A, said check-valve I 1a will become effective to close communication between the Pipe section I1 and the pipe 2|, while, if said.

brakes are operated through the medium of the manual control valve I8, the check-valve functions to close communication between the pipe sections I1' and I1, respectively. In Figures 2, 3 and5, 22 indicate the brake cam which when actuatedby power cylinder -I8 through cam lever 23 shown in Figure 1, forces brake shoes 24 out and against brake drum 25 which is attached to lower fifth wheel rotary base 26 so as to resist the turning effort of the upper and lower fth wheel duey to the fact that lock pawl 32 will keep the upper and lower fifth wheel from4 rotating about king pin 33. In Figures 2 and 3 retracting spring 43 serves to release the shoes from. contact with drum 25 when the power is released from chamber I8, this leaves the lower -fifth wheel 4I free to turn in fifth wheel base21.

The lower fifth wheel base 21 is fixed to pick-up plate 34 at flange 36. Pick-up plate 34 is attached to the tractor frame' 35. Pick-up plate 34 serves as a mounting for the lower fifth wheel and as an aid in coupling -the tractor to the semi-trailer. Lower fth wheel rotary base 26 is held in rotary position in fifth wheel base 21 by retaining plates 31. At 38 are brackets integral with fifthwheel rotary base 26, which carry losses 39 having a bearing hole for cross shaft 40, which supports vthe lower fifth wheel 4| through mounting brackets 42 s hown in Figures 4, 5, 6 and '7. In the' Figures 2, 3, 4 and 5, 44 indicated a lock to attach the upper fth wheel through king pin 33 to lower fifth wheel 4I. The lock 44 fulcrumed at 45 is retained in locking position through the medium of the latching notch 46 in the hand-actuatable lever 48 which is adapted to engage the nub'or projection 46a on the fifth wheel element 4I, the lever being held in itslocking position by spring 49. To

unlock the lower fth wheel 4I from upper fifth wheel king pin 33, hand lever 48 is pulled off its notched position against spring 48 and the lock is pulled to an open position by fulcruming about fulcrum pin 45.l Lower fifth wheel 4I has guide slot 50 through which king pin 33 is guided into position for coupling by lock 44. Guide slot 58 also servesas the locking slot vfor the reception e of lock pawl 32. Lock pawl 32 is fulcrumed at 5I and is held'in a locked position by spring 52, which tends to hold the engagement portion of the lock pawl 32 in-a locked position. The lock .pawl 32 is guided at its engagement and by lugs 53 which are integral with the king pin base 54. upper fifth wheel plate 55. Spring 58 attached at one end to the fifth wheel element 4I and at its other to the. 'tractor cab, or, any suitable fixed point in advance of said element, holds the lower fifth wheel 4I in the proper position for coupling of the tractor to the semi-trailer when in an uncoupled position. Inv coupling the tractor to the semi-trailer lock pawl 32 falls in slot 50 in the lower fifth wheel. 4I which will lock the upperand lower fifth wheel against relative radial motion. When the tractor brakes are applied the fifth wheel brake will resist any tendency for the semi-trailer and tractor to jackknife due to the application of the brake effort King pin base 54 is attached rto thel on the rotative brake'26 when decelerating the vehicle.

Having described my invention, I claim: l. In -a tractor-trailer train having a vehicle braking system. a fifth wheel having. means synchronized to function with said braking system to apply resistance to a relative horizontal movement between the tractor and the semi-trailer, when a brakeapplication is made on the tractortrailer train.

2. In combination with a'tractor and a trailer respectively embodying relatively rotatable elements constituting a fifth wheel, a braking system for retarding and arresting the movement of said tractor, a braking system for said trailer optionally operable with said tractor braking system and means synchronized with s aid tractor braking system for arresting the relative rotative movement of said fifth wheel forming elements solely ln response to the functioning of said tractor braking system.

3. A means for retarding relative horizontal angular' movement of a trailer and a self-propeller towing vehicle to which said trailer is coupled. including a fth. wheel between the trailer and the towingl vehicle embodying relatively rotatable supporting and supported components, braking mechanism associated with said fifth wheel adapted to retard and arrest the relative rotative movement of said components and means for connecting said mechanism to the braking system of the towing -vehicle to function in synchronization therewith.

4. The combination of a self-propelled towing vehicle having a" braking system and a trailer having a braking system coupled thereto, said coupling including a fth wheel and connections between the two braking systems, and braking meansfor said fth wheel, eective to control the pivotal movement of said trailerl on said fifth wheel, interconnected with Jthe braking system of said towing vehicle, said latter means functioning in synchronism with the towing vehicle braking system, whereby the application of braking effort on said towing yvehicle will simultaneously render said nfth wheel braking means effective. Y

5..'A fifth wheel construction, as lused in the coupling of a trailer to a self-propelled towing vehicle, comprising relatively rotatable members, means for controlling the relative rotative movement of said members and means for connecting said controlling means to the braking system of such towing `vehicle to function in synchronism therewith.

6. A means for retarding relative horizontal angular movement between ar trailer and a towing vehicle to which the trailer is coupled, in' cluding a fifth wheel between the trailer' and the towing vehicle, embodying relatively rotatable supporting and supported components, braking mechanism associated with said fifth wheel adapted to retard the relative rotative movement of by the application of the brakes ot the towing vehicle will simultaneously function said controlling means to exert effort effective to retard the relative rotational movement of said fifth wheel members.

8. A fth wheel construction, as used in the coupling of a trailer to a self-propelled. towing vehicle having a braking system, including relatively rotatable members ln bearing engage-.

ment, means for retardatively controlling the relative rotative movement of said members, means for connecting said controlling means to the braking system of the towing vehicle, whereby the application of thev brakes of the towing vehicle will simultaneously function said controlling means to exert eiort effective to retard the rela-.- tive rotational movement of said fth wheel members and means optionally operable to render said controlling means effective independently of the functioning of the towing vehicle braking system.

9. The' combination with a towing vehicle having a braking system and a trailer of means for connecting said trailer to the towing vehicle, said means including a fifth wheel to provide for relative horizontal angular movement between the two vehicles and mechanism for retardatively controlling such movement, said mechanism being connectable to said towing vehicle braking system and functioning in synchronism therewith.

10. The combination with a towing vehicle having a braking system and a trailer, of means for connecting said trailer to said-towing vehicle to provide for relative horizontal angular movement between the towing vehicle and the trailer during their conjoint operation and mechanism for retardatively controlling such movement, said mechanism being connectable to the braking system of said towing vehicle and becoming effective solely in response to the functioning of said braking system.

1l. A fifth wheel construction for coupling a trailer to a towing vehicle having a braking system, including a unit adapted to be rigidly connected to the trailer and embodying a king-pin, a unit adapted to be mountedl on such towing vehicle formed to receivethe king-pin of the trailer unit to connect said units for relatively rotational movement, braking means cooperative-- ly associated with one of said units and means for connecting said braking means to the braking system of the towing vehicle to operate in synchronism therewith, whereby relative horizontal angular movement of the vehicles coupled by said fth wheel may be retarded'simultaneously with the application of said braking system to the development of braking eort.

12. A means for retarding relative horizontal angular movement between a trailer and a towing vehicle to which the trailer is coupled, including a ith wheel betweenthe two vehicles. embodying relatively rotatable supporting and supported components, braking mechanism connected with said fifth wheel adapted to retard the relative rotative movement of said fth wheel components and means for functioning said mechanism in response to the operation of the braking system of the towing vehicle or independently thereof.

13. A means for retarding relative horizontal angular movement between a trailer and a tow-f,

ing vehicle coupled by a fifth wheel, including interconnectable rotatable components, braking mechanism associated with said iifth wheel adapted to retardatively control relative movement of said fth Wheel components and means for connecting said mechanism to the braking system of the towing vehicle for operation in conjunction therewith.

14. A means for controlling relative horizontal angular movement between a trailer and a towing vehicle connected by a fth wheel, embodyingI interconnectable relatively rotatable components, braking mechanism associated with said fth wheel operable to retard relative movement of said fifth wheel components and means optionally operable for connecting said mechanism to the braking'system of the towing vehicle for operation in conjunction therewith.

l5. 'Ihe combination with a towing vehicle having a fluid-operated braking system and a trailer, of means for connecting said trailer to the towing vehicle, said means including a fifth wheel, huid-operated mechanism for retardatively controlling relative horizontal angular movement between the two vehicles on the axis of said iifth wheel and means for connecting said mechanism to said towing vehicle for operation therefrom.

16. A fth wheel construction, as used in coupling a towing vehicle to a hauled vehicle,` comprising relatively rotatable members, means for controlling the relative rotative movement of said members, and optionally operable means for connecting said controlling means to the braking system of the hauled vehicle to function in synchronism therewith, or for eecting the operation of said means independently of such braking system.

HAROLD A. SOULIS.

vlli 

